/*!
 * mustache.js - Logic-less {{mustache}} templates with JavaScript
 * http://github.com/janl/mustache.js
 */

var objectToString = Object.prototype.toString;
var isArray = Array.isArray || function isArrayPolyfill(object) {
      return objectToString.call(object) === '[object Array]';
};

function isFunction(object) {
      return typeof object === 'function';
}

/**
 * More correct typeof string handling array
 * which normally returns typeof 'object'
 */
function typeStr(obj) {
      return isArray(obj) ? 'array' : typeof obj;
}

function escapeRegExp(string) {
      return string.replace(/[\-\[\]{}()*+?.,\\\^$|#\s]/g, '\\$&');
}

/**
 * Null safe way of checking whether or not an object,
 * including its prototype, has a given property
 */
function hasProperty(obj, propName) {
      return obj != null && typeof obj === 'object' && (propName in obj);
}

/**
 * Safe way of detecting whether or not the given thing is a primitive and
 * whether it has the given property
 */
function primitiveHasOwnProperty(primitive, propName) {
      return (
            primitive != null &&
            typeof primitive !== 'object' &&
            primitive.hasOwnProperty &&
            primitive.hasOwnProperty(propName)
      );
}

// Workaround for https://issues.apache.org/jira/browse/COUCHDB-577
// See https://github.com/janl/mustache.js/issues/189
var regExpTest = RegExp.prototype.test;

function testRegExp(re, string) {
      return regExpTest.call(re, string);
}

var nonSpaceRe = /\S/;

function isWhitespace(string) {
      return !testRegExp(nonSpaceRe, string);
}

var entityMap = {
      '&': '&amp;',
      '<': '&lt;',
      '>': '&gt;',
      '"': '&quot;',
      "'": '&#39;',
      '/': '&#x2F;',
      '`': '&#x60;',
      '=': '&#x3D;'
};

function escapeHtml(string) {
      return String(string).replace(/[&<>"'`=\/]/g, function fromEntityMap(s) {
            return entityMap[s];
      });
}

var whiteRe = /\s*/;
var spaceRe = /\s+/;
var equalsRe = /\s*=/;
var curlyRe = /\s*\}/;
var tagRe = /#|\^|\/|>|\{|&|=|!/;

/**
 * Breaks up the given `template` string into a tree of tokens. If the `tags`
 * argument is given here it must be an array with two string values: the
 * opening and closing tags used in the template (e.g. [ "<%", "%>" ]). Of
 * course, the default is to use mustaches (i.e. mustache.tags).
 *
 * A token is an array with at least 4 elements. The first element is the
 * mustache symbol that was used inside the tag, e.g. "#" or "&". If the tag
 * did not contain a symbol (i.e. {{myValue}}) this element is "name". For
 * all text that appears outside a symbol this element is "text".
 *
 * The second element of a token is its "value". For mustache tags this is
 * whatever else was inside the tag besides the opening symbol. For text tokens
 * this is the text itself.
 *
 * The third and fourth elements of the token are the start and end indices,
 * respectively, of the token in the original template.
 *
 * Tokens that are the root node of a subtree contain two more elements: 1) an
 * array of tokens in the subtree and 2) the index in the original template at
 * which the closing tag for that section begins.
 *
 * Tokens for partials also contain two more elements: 1) a string value of
 * indendation prior to that tag and 2) the index of that tag on that line -
 * eg a value of 2 indicates the partial is the third tag on this line.
 */
function parseTemplate(template, tags) {
      if (!template)
            return [];
      var lineHasNonSpace = false;
      var sections = []; // Stack to hold section tokens
      var tokens = []; // Buffer to hold the tokens
      var spaces = []; // Indices of whitespace tokens on the current line
      var hasTag = false; // Is there a {{tag}} on the current line?
      var nonSpace = false; // Is there a non-space char on the current line?
      var indentation = ''; // Tracks indentation for tags that use it
      var tagIndex = 0; // Stores a count of number of tags encountered on a line

      // Strips all whitespace tokens array for the current line
      // if there was a {{#tag}} on it and otherwise only space.
      function stripSpace() {
            if (hasTag && !nonSpace) {
                  while (spaces.length)
                        delete tokens[spaces.pop()];
            } else {
                  spaces = [];
            }

            hasTag = false;
            nonSpace = false;
      }

      var openingTagRe, closingTagRe, closingCurlyRe;

      function compileTags(tagsToCompile) {
            if (typeof tagsToCompile === 'string')
                  tagsToCompile = tagsToCompile.split(spaceRe, 2);

            if (!isArray(tagsToCompile) || tagsToCompile.length !== 2)
                  throw new Error('Invalid tags: ' + tagsToCompile);

            openingTagRe = new RegExp(escapeRegExp(tagsToCompile[0]) + '\\s*');
            closingTagRe = new RegExp('\\s*' + escapeRegExp(tagsToCompile[1]));
            closingCurlyRe = new RegExp('\\s*' + escapeRegExp('}' + tagsToCompile[1]));
      }

      compileTags(tags || mustache.tags);

      var scanner = new Scanner(template);

      var start, type, value, chr, token, openSection;
      while (!scanner.eos()) {
            start = scanner.pos;

            // Match any text between tags.
            value = scanner.scanUntil(openingTagRe);

            if (value) {
                  for (var i = 0, valueLength = value.length; i < valueLength; ++i) {
                        chr = value.charAt(i);

                        if (isWhitespace(chr)) {
                              spaces.push(tokens.length);
                              indentation += chr;
                        } else {
                              nonSpace = true;
                              lineHasNonSpace = true;
                              indentation += ' ';
                        }

                        tokens.push(['text', chr, start, start + 1]);
                        start += 1;

                        // Check for whitespace on the current line.
                        if (chr === '\n') {
                              stripSpace();
                              indentation = '';
                              tagIndex = 0;
                              lineHasNonSpace = false;
                        }
                  }
            }

            // Match the opening tag.
            if (!scanner.scan(openingTagRe))
                  break;

            hasTag = true;

            // Get the tag type.
            type = scanner.scan(tagRe) || 'name';
            scanner.scan(whiteRe);

            // Get the tag value.
            if (type === '=') {
                  value = scanner.scanUntil(equalsRe);
                  scanner.scan(equalsRe);
                  scanner.scanUntil(closingTagRe);
            } else if (type === '{') {
                  value = scanner.scanUntil(closingCurlyRe);
                  scanner.scan(curlyRe);
                  scanner.scanUntil(closingTagRe);
                  type = '&';
            } else {
                  value = scanner.scanUntil(closingTagRe);
            }

            // Match the closing tag.
            if (!scanner.scan(closingTagRe))
                  throw new Error('Unclosed tag at ' + scanner.pos);

            if (type == '>') {
                  token = [type, value, start, scanner.pos, indentation, tagIndex, lineHasNonSpace];
            } else {
                  token = [type, value, start, scanner.pos];
            }
            tagIndex++;
            tokens.push(token);

            if (type === '#' || type === '^') {
                  sections.push(token);
            } else if (type === '/') {
                  // Check section nesting.
                  openSection = sections.pop();

                  if (!openSection)
                        throw new Error('Unopened section "' + value + '" at ' + start);

                  if (openSection[1] !== value)
                        throw new Error('Unclosed section "' + openSection[1] + '" at ' + start);
            } else if (type === 'name' || type === '{' || type === '&') {
                  nonSpace = true;
            } else if (type === '=') {
                  // Set the tags for the next time around.
                  compileTags(value);
            }
      }

      stripSpace();

      // Make sure there are no open sections when we're done.
      openSection = sections.pop();

      if (openSection)
            throw new Error('Unclosed section "' + openSection[1] + '" at ' + scanner.pos);

      return nestTokens(squashTokens(tokens));
}

/**
 * Combines the values of consecutive text tokens in the given `tokens` array
 * to a single token.
 */
function squashTokens(tokens) {
      var squashedTokens = [];

      var token, lastToken;
      for (var i = 0, numTokens = tokens.length; i < numTokens; ++i) {
            token = tokens[i];

            if (token) {
                  if (token[0] === 'text' && lastToken && lastToken[0] === 'text') {
                        lastToken[1] += token[1];
                        lastToken[3] = token[3];
                  } else {
                        squashedTokens.push(token);
                        lastToken = token;
                  }
            }
      }

      return squashedTokens;
}

/**
 * Forms the given array of `tokens` into a nested tree structure where
 * tokens that represent a section have two additional items: 1) an array of
 * all tokens that appear in that section and 2) the index in the original
 * template that represents the end of that section.
 */
function nestTokens(tokens) {
      var nestedTokens = [];
      var collector = nestedTokens;
      var sections = [];

      var token, section;
      for (var i = 0, numTokens = tokens.length; i < numTokens; ++i) {
            token = tokens[i];

            switch (token[0]) {
                  case '#':
                  case '^':
                        collector.push(token);
                        sections.push(token);
                        collector = token[4] = [];
                        break;
                  case '/':
                        section = sections.pop();
                        section[5] = token[2];
                        collector = sections.length > 0 ? sections[sections.length - 1][4] : nestedTokens;
                        break;
                  default:
                        collector.push(token);
            }
      }

      return nestedTokens;
}

/**
 * A simple string scanner that is used by the template parser to find
 * tokens in template strings.
 */
function Scanner(string) {
      this.string = string;
      this.tail = string;
      this.pos = 0;
}

/**
 * Returns `true` if the tail is empty (end of string).
 */
Scanner.prototype.eos = function eos() {
      return this.tail === '';
};

/**
 * Tries to match the given regular expression at the current position.
 * Returns the matched text if it can match, the empty string otherwise.
 */
Scanner.prototype.scan = function scan(re) {
      var match = this.tail.match(re);

      if (!match || match.index !== 0)
            return '';

      var string = match[0];

      this.tail = this.tail.substring(string.length);
      this.pos += string.length;

      return string;
};

/**
 * Skips all text until the given regular expression can be matched. Returns
 * the skipped string, which is the entire tail if no match can be made.
 */
Scanner.prototype.scanUntil = function scanUntil(re) {
      var index = this.tail.search(re),
            match;

      switch (index) {
            case -1:
                  match = this.tail;
                  this.tail = '';
                  break;
            case 0:
                  match = '';
                  break;
            default:
                  match = this.tail.substring(0, index);
                  this.tail = this.tail.substring(index);
      }

      this.pos += match.length;

      return match;
};

/**
 * Represents a rendering context by wrapping a view object and
 * maintaining a reference to the parent context.
 */
function Context(view, parentContext) {
      this.view = view;
      this.cache = {
            '.': this.view
      };
      this.parent = parentContext;
}

/**
 * Creates a new context using the given view with this context
 * as the parent.
 */
Context.prototype.push = function push(view) {
      return new Context(view, this);
};

/**
 * Returns the value of the given name in this context, traversing
 * up the context hierarchy if the value is absent in this context's view.
 */
Context.prototype.lookup = function lookup(name) {
      var cache = this.cache;

      var value;
      if (cache.hasOwnProperty(name)) {
            value = cache[name];
      } else {
            var context = this,
                  intermediateValue, names, index, lookupHit = false;

            while (context) {
                  if (name.indexOf('.') > 0) {
                        intermediateValue = context.view;
                        names = name.split('.');
                        index = 0;

                        /**
                         * Using the dot notion path in `name`, we descend through the
                         * nested objects.
                         *
                         * To be certain that the lookup has been successful, we have to
                         * check if the last object in the path actually has the property
                         * we are looking for. We store the result in `lookupHit`.
                         *
                         * This is specially necessary for when the value has been set to
                         * `undefined` and we want to avoid looking up parent contexts.
                         *
                         * In the case where dot notation is used, we consider the lookup
                         * to be successful even if the last "object" in the path is
                         * not actually an object but a primitive (e.g., a string, or an
                         * integer), because it is sometimes useful to access a property
                         * of an autoboxed primitive, such as the length of a string.
                         **/
                        while (intermediateValue != null && index < names.length) {
                              if (index === names.length - 1)
                                    lookupHit = (
                                          hasProperty(intermediateValue, names[index]) ||
                                          primitiveHasOwnProperty(intermediateValue, names[index])
                                    );

                              intermediateValue = intermediateValue[names[index++]];
                        }
                  } else {
                        intermediateValue = context.view[name];

                        /**
                         * Only checking against `hasProperty`, which always returns `false` if
                         * `context.view` is not an object. Deliberately omitting the check
                         * against `primitiveHasOwnProperty` if dot notation is not used.
                         *
                         * Consider this example:
                         * ```
                         * Mustache.render("The length of a football field is {{#length}}{{length}}{{/length}}.", {length: "100 yards"})
                         * ```
                         *
                         * If we were to check also against `primitiveHasOwnProperty`, as we do
                         * in the dot notation case, then render call would return:
                         *
                         * "The length of a football field is 9."
                         *
                         * rather than the expected:
                         *
                         * "The length of a football field is 100 yards."
                         **/
                        lookupHit = hasProperty(context.view, name);
                  }

                  if (lookupHit) {
                        value = intermediateValue;
                        break;
                  }

                  context = context.parent;
            }

            cache[name] = value;
      }

      if (isFunction(value))
            value = value.call(this.view);

      return value;
};

/**
 * A Writer knows how to take a stream of tokens and render them to a
 * string, given a context. It also maintains a cache of templates to
 * avoid the need to parse the same template twice.
 */
function Writer() {
      this.templateCache = {
            _cache: {},
            set: function set(key, value) {
                  this._cache[key] = value;
            },
            get: function get(key) {
                  return this._cache[key];
            },
            clear: function clear() {
                  this._cache = {};
            }
      };
}

/**
 * Clears all cached templates in this writer.
 */
Writer.prototype.clearCache = function clearCache() {
      if (typeof this.templateCache !== 'undefined') {
            this.templateCache.clear();
      }
};

/**
 * Parses and caches the given `template` according to the given `tags` or
 * `mustache.tags` if `tags` is omitted,  and returns the array of tokens
 * that is generated from the parse.
 */
Writer.prototype.parse = function parse(template, tags) {
      var cache = this.templateCache;
      var cacheKey = template + ':' + (tags || mustache.tags).join(':');
      var isCacheEnabled = typeof cache !== 'undefined';
      var tokens = isCacheEnabled ? cache.get(cacheKey) : undefined;

      if (tokens == undefined) {
            tokens = parseTemplate(template, tags);
            isCacheEnabled && cache.set(cacheKey, tokens);
      }
      return tokens;
};

/**
 * High-level method that is used to render the given `template` with
 * the given `view`.
 *
 * The optional `partials` argument may be an object that contains the
 * names and templates of partials that are used in the template. It may
 * also be a function that is used to load partial templates on the fly
 * that takes a single argument: the name of the partial.
 *
 * If the optional `config` argument is given here, then it should be an
 * object with a `tags` attribute or an `escape` attribute or both.
 * If an array is passed, then it will be interpreted the same way as
 * a `tags` attribute on a `config` object.
 *
 * The `tags` attribute of a `config` object must be an array with two
 * string values: the opening and closing tags used in the template (e.g.
 * [ "<%", "%>" ]). The default is to mustache.tags.
 *
 * The `escape` attribute of a `config` object must be a function which
 * accepts a string as input and outputs a safely escaped string.
 * If an `escape` function is not provided, then an HTML-safe string
 * escaping function is used as the default.
 */
Writer.prototype.render = function render(template, view, partials, config) {
      var tags = this.getConfigTags(config);
      var tokens = this.parse(template, tags);
      var context = (view instanceof Context) ? view : new Context(view, undefined);
      return this.renderTokens(tokens, context, partials, template, config);
};

/**
 * Low-level method that renders the given array of `tokens` using
 * the given `context` and `partials`.
 *
 * Note: The `originalTemplate` is only ever used to extract the portion
 * of the original template that was contained in a higher-order section.
 * If the template doesn't use higher-order sections, this argument may
 * be omitted.
 */
Writer.prototype.renderTokens = function renderTokens(tokens, context, partials, originalTemplate, config) {
      var buffer = '';

      var token, symbol, value;
      for (var i = 0, numTokens = tokens.length; i < numTokens; ++i) {
            value = undefined;
            token = tokens[i];
            symbol = token[0];

            if (symbol === '#') value = this.renderSection(token, context, partials, originalTemplate, config);
            else if (symbol === '^') value = this.renderInverted(token, context, partials, originalTemplate, config);
            else if (symbol === '>') value = this.renderPartial(token, context, partials, config);
            else if (symbol === '&') value = this.unescapedValue(token, context);
            else if (symbol === 'name') value = this.escapedValue(token, context, config);
            else if (symbol === 'text') value = this.rawValue(token);

            if (value !== undefined)
                  buffer += value;
      }

      return buffer;
};

Writer.prototype.renderSection = function renderSection(token, context, partials, originalTemplate, config) {
      var self = this;
      var buffer = '';
      var value = context.lookup(token[1]);

      // This function is used to render an arbitrary template
      // in the current context by higher-order sections.
      function subRender(template) {
            return self.render(template, context, partials, config);
      }

      if (!value) return;

      if (isArray(value)) {
            for (var j = 0, valueLength = value.length; j < valueLength; ++j) {
                  buffer += this.renderTokens(token[4], context.push(value[j]), partials, originalTemplate, config);
            }
      } else if (typeof value === 'object' || typeof value === 'string' || typeof value === 'number') {
            buffer += this.renderTokens(token[4], context.push(value), partials, originalTemplate, config);
      } else if (isFunction(value)) {
            if (typeof originalTemplate !== 'string')
                  throw new Error('Cannot use higher-order sections without the original template');

            // Extract the portion of the original template that the section contains.
            value = value.call(context.view, originalTemplate.slice(token[3], token[5]), subRender);

            if (value != null)
                  buffer += value;
      } else {
            buffer += this.renderTokens(token[4], context, partials, originalTemplate, config);
      }
      return buffer;
};

Writer.prototype.renderInverted = function renderInverted(token, context, partials, originalTemplate, config) {
      var value = context.lookup(token[1]);

      // Use JavaScript's definition of falsy. Include empty arrays.
      // See https://github.com/janl/mustache.js/issues/186
      if (!value || (isArray(value) && value.length === 0))
            return this.renderTokens(token[4], context, partials, originalTemplate, config);
};

Writer.prototype.indentPartial = function indentPartial(partial, indentation, lineHasNonSpace) {
      var filteredIndentation = indentation.replace(/[^ \t]/g, '');
      var partialByNl = partial.split('\n');
      for (var i = 0; i < partialByNl.length; i++) {
            if (partialByNl[i].length && (i > 0 || !lineHasNonSpace)) {
                  partialByNl[i] = filteredIndentation + partialByNl[i];
            }
      }
      return partialByNl.join('\n');
};

Writer.prototype.renderPartial = function renderPartial(token, context, partials, config) {
      if (!partials) return;
      var tags = this.getConfigTags(config);

      var value = isFunction(partials) ? partials(token[1]) : partials[token[1]];
      if (value != null) {
            var lineHasNonSpace = token[6];
            var tagIndex = token[5];
            var indentation = token[4];
            var indentedValue = value;
            if (tagIndex == 0 && indentation) {
                  indentedValue = this.indentPartial(value, indentation, lineHasNonSpace);
            }
            var tokens = this.parse(indentedValue, tags);
            return this.renderTokens(tokens, context, partials, indentedValue, config);
      }
};

Writer.prototype.unescapedValue = function unescapedValue(token, context) {
      var value = context.lookup(token[1]);
      if (value != null)
            return value;
};

Writer.prototype.escapedValue = function escapedValue(token, context, config) {
      var escape = this.getConfigEscape(config) || mustache.escape;
      var value = context.lookup(token[1]);
      if (value != null)
            return (typeof value === 'number' && escape === mustache.escape) ? String(value) : escape(value);
};

Writer.prototype.rawValue = function rawValue(token) {
      return token[1];
};

Writer.prototype.getConfigTags = function getConfigTags(config) {
      if (isArray(config)) {
            return config;
      } else if (config && typeof config === 'object') {
            return config.tags;
      } else {
            return undefined;
      }
};

Writer.prototype.getConfigEscape = function getConfigEscape(config) {
      if (config && typeof config === 'object' && !isArray(config)) {
            return config.escape;
      } else {
            return undefined;
      }
};

var mustache = {
      name: 'mustache.js',
      version: '4.2.0',
      tags: ['{{', '}}'],
      clearCache: undefined,
      escape: undefined,
      parse: undefined,
      render: undefined,
      Scanner: undefined,
      Context: undefined,
      Writer: undefined,
      /**
       * Allows a user to override the default caching strategy, by providing an
       * object with set, get and clear methods. This can also be used to disable
       * the cache by setting it to the literal `undefined`.
       */
      set templateCache(cache) {
            defaultWriter.templateCache = cache;
      },
      /**
       * Gets the default or overridden caching object from the default writer.
       */
      get templateCache() {
            return defaultWriter.templateCache;
      }
};

// All high-level mustache.* functions use this writer.
var defaultWriter = new Writer();

/**
 * Clears all cached templates in the default writer.
 */
mustache.clearCache = function clearCache() {
      return defaultWriter.clearCache();
};

/**
 * Parses and caches the given template in the default writer and returns the
 * array of tokens it contains. Doing this ahead of time avoids the need to
 * parse templates on the fly as they are rendered.
 */
mustache.parse = function parse(template, tags) {
      return defaultWriter.parse(template, tags);
};

/**
 * Renders the `template` with the given `view`, `partials`, and `config`
 * using the default writer.
 */
mustache.render = function render(template, view, partials, config) {
      if (typeof template !== 'string') {
            throw new TypeError('Invalid template! Template should be a "string" ' +
                  'but "' + typeStr(template) + '" was given as the first ' +
                  'argument for mustache#render(template, view, partials)');
      }

      return defaultWriter.render(template, view, partials, config);
};

// Export the escaping function so that the user may override it.
// See https://github.com/janl/mustache.js/issues/244
mustache.escape = escapeHtml;

// Export these mainly for testing, but also for advanced usage.
mustache.Scanner = Scanner;
mustache.Context = Context;
mustache.Writer = Writer;

export default mustache;